阅读说明：本技术 一种磁催化氧化除磷工艺及除磷系统 (Magnetic catalytic oxidation phosphorus removal process and phosphorus removal system ) 是由 徐少华 袁宝 凌文忠 范远红 于 2021-07-31 设计创作，主要内容包括：本发明涉及工业废水处理的技术领域,更具体地,涉及一种磁催化氧化除磷工艺及除磷系统,包括以下步骤：工业废水进入调节池并加酸调节工业废水的PH值；向工业废水中加入双氧水并搅拌均匀,再依次添加去除剂和磁催化剂,搅拌反应；向工业废水中加碱回调工业废水的PH,加入絮凝剂搅拌,形成磁性絮团；含磁性絮团的工业废水流入沉淀池内沉淀,沉淀池上部得到上清液、底部得到磁性污泥；调节上清液PH至中性达标排放或进入后处理工艺,磁性污泥进入磁催化剂回收系统回收磁催化剂。本发明的次催化氧化除磷工艺及除磷系统,类芬顿氧化与共沉淀协同作用深度除磷,不需要将次亚磷完全氧化为正磷,可缩短反应时间和沉降时间,减少药剂用量,改善除磷效果。(The invention relates to the technical field of industrial wastewater treatment, in particular to a magnetic catalytic oxidation phosphorus removal process and a phosphorus removal system, which comprise the following steps: the industrial wastewater enters a regulating tank and is added with acid to regulate the pH value of the industrial wastewater; adding hydrogen peroxide into the industrial wastewater, uniformly stirring, sequentially adding a remover and a magnetic catalyst, and stirring for reaction; adding alkali into the industrial wastewater to adjust back the pH value of the industrial wastewater, adding a flocculating agent, and stirring to form a magnetic floccule; the industrial wastewater containing the magnetic floccules flows into a sedimentation tank for sedimentation, supernatant fluid is obtained at the upper part of the sedimentation tank, and magnetic sludge is obtained at the bottom of the sedimentation tank; and (4) adjusting the PH of the supernatant to be neutral and discharged after reaching the standard or entering a post-treatment process, and enabling the magnetic sludge to enter a magnetic catalyst recovery system to recover the magnetic catalyst. The sub-catalytic oxidation phosphorus removal process and the phosphorus removal system have the advantages that the Fenton-like oxidation and coprecipitation are synergistic to deeply remove phosphorus, the hypophosphorous acid is not required to be completely oxidized into the orthophosphoric acid, the reaction time and the sedimentation time can be shortened, the dosage of the medicament is reduced, and the phosphorus removal effect is improved.)

1. A process for removing phosphorus by magnetic catalytic oxidation is characterized by comprising the following steps:

s10, the industrial wastewater enters a regulating tank (1) and is added with acid to regulate the pH value of the industrial wastewater to 1-3;

s20, adding hydrogen peroxide into the industrial wastewater, uniformly stirring, sequentially adding a remover and a magnetic catalyst, stirring for reaction, hydrolyzing the remover to obtain metal ions, wherein the metal ions comprise Fe²⁺The magnetic catalyst is hydrolyzed to obtain Fe²⁺、Fe³⁺；

The metal ions react with hydrogen peroxide under acidic conditions to form hydroxyl radicals which are oxidized with phosphorous to form Fe^{2 +}Promoting said oxidation reaction, Fe³⁺Co-precipitation with phosphorous;

s30, adding alkali into the industrial wastewater to adjust the pH value of the industrial wastewater back to 5-7, adding a flocculating agent, and stirring to form magnetic floccules in the industrial wastewater; the industrial wastewater containing the magnetic floccules flows into a sedimentation tank (2) for sedimentation, supernatant is obtained at the upper part of the sedimentation tank (2), and magnetic sludge is obtained at the bottom;

and S40, adjusting the PH value of the supernatant to be neutral and discharged after reaching the standard or entering a post-treatment process, wherein the magnetic sludge enters a magnetic catalyst recovery system (3) to recover a magnetic catalyst, and the recovered magnetic catalyst returns to the adjusting tank to participate in the reaction.

2. The process for removing phosphorus through magnetic catalytic oxidation as claimed in claim 1, wherein in step S20, the removing agent comprises the following components by mass percent: 10 to 30 percent of aluminum sulfate; 0.5 to 5 percent of copper sulfate; 30-60% of anhydrous ferrous sulfate; 15 to 30 percent of magnesium sulfate.

3. The magnetically catalyzed oxidative phosphorus removal process of claim 1, wherein in step S20, the magnetic catalyst is a mixture of ferroferric oxide and ferric oxide, and the mass ratio of the ferroferric oxide to the ferric oxide is 1: 1-10: 1.

4. the process for removing phosphorus through magnetic catalytic oxidation as claimed in claim 1, wherein in step S20, the adding mass of hydrogen peroxide is 6-25 times of the total phosphorus mass, the adding mass of the removing agent is 8-15 times of the total phosphorus mass, and the adding mass of the magnetic catalyst is 2-50 times of the total phosphorus mass.

5. The process for removing phosphorus by magnetic catalytic oxidation as claimed in claim 4, wherein the removing agent solid is added and the magnetic catalyst solid is added.

6. The process for removing phosphorus through magnetic catalytic oxidation as claimed in claim 4, wherein the remover is added in a liquid form in a 5% -35% solution prepared by clear water, and the magnetic catalyst is added in a solid form.

7. The magnetically catalyzed oxidative phosphorus removal process of claim 1, wherein in step S30, the flocculant is a PAM flocculant.

8. The process for removing phosphorus by magnetic catalytic oxidation as claimed in any one of claims 1 to 7, wherein the magnetic catalyst recovery system (3) recovers the magnetic catalyst by the following steps: after the magnetic catalyst and the excess sludge are separated through the mechanical shearing action, the magnetic catalyst is salvaged based on the magnetic action, the excess sludge is discharged and treated, and the magnetic catalyst returns to the regulating tank (1) to participate in the reaction.

9. The magnetic catalytic oxidation phosphorus removal system is characterized by comprising a regulating tank (1), a sedimentation tank (2) and a magnetic catalyst recovery system (3): the adjusting tank (1) is communicated with the settling tank (2), the adjusting tank (1) is provided with a medicament adding system (4) for adding a medicament and a stirring system (5) for reaction and stirring, the bottom of the settling tank (2) is communicated with a magnetic catalyst recovery system (3), and the magnetic catalyst recovery system (3) is communicated with the adjusting tank (1); what is needed isThe preparation comprises hydrogen peroxide, a remover, a magnetic catalyst and a flocculating agent, wherein the remover is hydrolyzed to obtain metal ions, and the metal ions comprise Fe²⁺The magnetic catalyst is hydrolyzed to obtain Fe²⁺、Fe³⁺The metal ions react with hydrogen peroxide under acidic conditions to form hydroxyl radicals which are oxidized with phosphorous to form Fe²⁺Promoting said oxidation reaction, Fe³⁺Co-precipitation with phosphorous; under the action of magnetic catalyst and flocculant, the suspended matter forms magnetic flocs.

10. The system for removing phosphorus through magnetic catalytic oxidation according to claim 9, wherein the system for recovering magnetic catalyst (3) comprises a sludge pump (31), a dispersion machine (32) and a magnetic circulation machine (33) which are arranged in sequence, the sludge pump (31) sends the magnetic sludge pump (31) at the bottom of the sedimentation tank (2) to the dispersion machine (32), the dispersion machine (32) separates the magnetic catalyst from the residual sludge, and the magnetic circulation machine (33) returns the magnetic catalyst to the regulating tank (1).

Technical Field

The invention relates to the technical field of industrial wastewater treatment, and particularly relates to a magnetic catalytic oxidation phosphorus removal process and a phosphorus removal system.

Background

Reducing agent is commonly used in the industries of electroplating, circuit board printing and the like to reduce and deposit ions in the plating solution on the surface of a plated part so as to finish the plated parts with various shapes and materials. The reducing agent used is mainly sodium hypophosphite, resulting in residual hypophosphite in the industrial waste water produced. The difficulty in removing the hypophosphite in the industrial wastewater is high, the traditional treatment processes comprise a Fenton advanced oxidation method, a sodium hypochlorite oxidation method, a resin method and the like, but the problems of incomplete removal, high treatment cost, long reaction time, poor settling effect, large occupied area and the like exist.

Chinese patent CN111875129A discloses a method for treating hypophosphite and phosphite wastewater, which comprises the following steps: s1, acidifying wastewater: taking a proper amount of wastewater, adding ferrous sulfate heptahydrate into the hypophosphite and phosphite wastewater, stirring until the ferrous sulfate heptahydrate is completely dissolved, adding a sulfuric acid solution to adjust the pH value of the wastewater to 3-4, and stirring for 0.5-1 hour; s2, oxidizing hypophosphites and phosphites are orthophosphates: adding hydrogen peroxide into the solution obtained in the step S1, continuously stirring for reaction, and standing to obtain an orthophosphate wastewater solution; s3, precipitated phosphate: and (4) adding excessive calcium oxide into the phosphate wastewater solution obtained in the step S2, stirring for reaction, adding ammonia water, stirring for 0.5-1 hour, standing, filtering to remove calcium hydroxide and calcium phosphate salt, and discharging the wastewater until the phosphorus content reaches the standard. The scheme adopts an oxidation method to treat the hypophosphite, so that the reaction time and the settling time are long, the using amount of the oxidant is large, the removal rate is low, and the final effluent total phosphorus is easy to exceed the standard.

Disclosure of Invention

The invention aims to overcome the defects in the prior art and provide a magnetic catalytic oxidation phosphorus removal process and a phosphorus removal system, which do not need to completely oxidize hypophosphorous acid into orthophosphoric acid, can shorten the reaction time and the settling time, reduce the dosage of a medicament and improve the phosphorus removal effect.

In order to solve the technical problems, the invention adopts the technical scheme that:

provides a magnetic catalytic oxidation dephosphorization process, which comprises the following steps:

s10, the industrial wastewater enters a regulating tank and is added with acid to regulate the pH value of the industrial wastewater to 1-3;

s20, adding hydrogen peroxide into the industrial wastewater, uniformly stirring, sequentially adding a remover and a magnetic catalyst, stirring for reaction, hydrolyzing the remover to obtain metal ions, wherein the metal ions comprise Fe²⁺The magnetic catalyst is hydrolyzed to obtain Fe²⁺、Fe³⁺；

The metal ions react with hydrogen peroxide under acidic conditions to form hydroxyl radicals which are oxidized with phosphorous to form Fe²⁺Promoting said oxidation reaction, Fe³⁺Co-precipitation with phosphorous;

s30, adding alkali into the industrial wastewater to adjust the pH value of the industrial wastewater back to 5-7, adding a flocculating agent, and stirring to form magnetic floccules in the industrial wastewater; the industrial wastewater containing the magnetic floccules flows into a sedimentation tank for sedimentation, supernatant fluid is obtained at the upper part of the sedimentation tank, and magnetic sludge is obtained at the bottom of the sedimentation tank;

and S40, adjusting the PH value of the supernatant to be neutral and discharged after reaching the standard or entering a post-treatment process, and enabling the magnetic sludge to enter a magnetic catalyst recovery system to recover the magnetic catalyst.

The invention relates to a magnetic catalytic oxidation dephosphorization process, wherein a remover is hydrolyzed to obtain Fe²⁺Reacting the metal ions with hydrogen peroxide to form hydroxyl radicals under an acidic condition, wherein the hydroxyl radicals efficiently oxidize the hypophosphorous acid;hydrolyzing the magnetic catalyst to obtain Fe²⁺、Fe³⁺，Fe²⁺Promoting said oxidation reaction, Fe³⁺Directly forming coprecipitation with hypophosphorous acid; and then, under the action of a magnetic catalyst and a flocculating agent, suspended matters in the industrial wastewater form magnetic floccules, the magnetic catalyst can be used as a magnetic core for solid-liquid separation and sedimentation, sedimentation is accelerated, the content of the suspended matters in the supernatant is reduced, the total phosphorus removal rate is improved, the pH of the supernatant is adjusted to be neutral and discharged after reaching the standard, the magnetic sludge enters a magnetic catalyst recovery system to recover the magnetic catalyst, and the recovered magnetic catalyst can be recycled. The sub-catalytic oxidation phosphorus removal process has the advantages that the Fenton-like oxidation and coprecipitation are synergistic to deeply remove phosphorus, the sub-phosphorous is not required to be completely oxidized into the ortho-phosphorous, the reaction time and the sedimentation time can be shortened, the dosage of the medicament is reduced, and the phosphorus removal effect is improved.

Preferably, in step S20, the remover comprises the following components in percentage by mass: 10 to 30 percent of aluminum sulfate; 0.5 to 5 percent of copper sulfate; 30-60% of anhydrous ferrous sulfate; 15 to 30 percent of magnesium sulfate.

Preferably, in step S20, the magnetic catalyst is a mixture of ferroferric oxide and ferric oxide, and the mass ratio of the ferroferric oxide to the ferric oxide is 1: 1-10: 1.

preferably, in step S20, the adding mass of the hydrogen peroxide is 6-25 times of the total phosphorus mass, the adding mass of the remover is 8-15 times of the total phosphorus mass, and the adding mass of the magnetic catalyst is 2-50 times of the total phosphorus mass.

Preferably, the remover solid is added and the magnetic catalyst solid is added.

Preferably, the remover is prepared into a solution with the concentration of 5-35% by using clear water for liquid adding, and the magnetic catalyst is added in a solid manner.

Preferably, in step S30, the flocculant is a PAM flocculant.

Preferably, the magnetic catalyst recovery system recovers the magnetic catalyst according to the following steps: after the magnetic catalyst and the excess sludge are separated through the mechanical shearing action, the magnetic catalyst is salvaged based on the magnetic action, the excess sludge is discharged and treated, and the magnetic catalyst returns to the regulating reservoir to participate in the reaction.

The invention also provides a magnetic catalytic oxidation dephosphorization system, which comprises a regulating tank, a sedimentation tank and a magnetic catalyst recovery system: the adjusting tank is communicated with the sedimentation tank, the adjusting tank is provided with a medicament adding system for adding a medicament and a stirring system for reaction stirring, the bottom of the sedimentation tank is communicated with a magnetic catalyst recovery system, and the magnetic catalyst recovery system is communicated with the adjusting tank; the medicament comprises hydrogen peroxide, a remover, a magnetic catalyst and a flocculating agent, wherein the remover is hydrolyzed to obtain metal ions, and the metal ions comprise Fe²⁺The magnetic catalyst is hydrolyzed to obtain Fe²⁺、Fe³⁺The metal ions react with hydrogen peroxide under acidic conditions to form hydroxyl radicals which are oxidized with phosphorous to form Fe²⁺Promoting said oxidation reaction, Fe³⁺Co-precipitation with phosphorous; under the action of magnetic catalyst and flocculant, the suspended matter forms magnetic flocs.

According to the magnetic catalytic oxidation phosphorus removal system, the remover is hydrolyzed to obtain Fe²⁺Reacting the metal ions with hydrogen peroxide to form hydroxyl radicals under an acidic condition, wherein the hydroxyl radicals efficiently oxidize the hypophosphorous acid; hydrolyzing the magnetic catalyst to obtain Fe²⁺、Fe³⁺，Fe²⁺Promoting said oxidation reaction, Fe³⁺Directly forming coprecipitation with hypophosphorous acid; and then, under the action of a magnetic catalyst and a flocculating agent, suspended matters in the industrial wastewater form magnetic floccules, the magnetic catalyst can be used as a magnetic core for solid-liquid separation and sedimentation, sedimentation is accelerated, the content of the suspended matters in the supernatant is reduced, the total phosphorus removal rate is improved, the pH of the supernatant is adjusted to be neutral and discharged after reaching the standard, the magnetic sludge enters a magnetic catalyst recovery system to recover the magnetic catalyst, and the recovered magnetic catalyst can be recycled. The sub-catalytic oxidation phosphorus removal system disclosed by the invention adopts Fenton-like oxidation and coprecipitation synergistic action to deeply remove phosphorus, does not need to completely oxidize the hypophosphorous acid into the orthophosphoric acid, can shorten the reaction time and the settling time, reduces the dosage of a medicament and improves the phosphorus removal effect.

Further, magnetic catalyst recovery system is including the sludge pump, dispenser and the magnetic cycle machine that set gradually, and the sludge pump is with the magnetic sludge pump of sedimentation tank bottom to the dispenser, and the dispenser is with magnetic catalyst and surplus mud separation, and the magnetic cycle machine returns the magnetic catalyst to the equalizing basin.

Compared with the prior art, the invention has the beneficial effects that:

the sub-catalytic oxidation phosphorus removal process and the phosphorus removal system have the advantages that the Fenton-like oxidation and coprecipitation are synergistic to deeply remove phosphorus, the hypophosphorous acid is not required to be completely oxidized into the orthophosphoric acid, the reaction time and the sedimentation time can be shortened, the dosage of the medicament is reduced, and the phosphorus removal effect is improved.

Drawings

FIG. 1 is a schematic diagram of a process for removing phosphorus by magnetic catalytic oxidation;

FIG. 2 is a schematic diagram of a system for removing phosphorus by magnetic catalytic oxidation;

in the drawings: 1-a regulating reservoir; 2. a sedimentation tank; 3. a magnetic catalyst recovery system; 31. a sludge pump; 32. a dispersion machine; 33. a magnetic circulator; 4. a medicament dosing system; 5. a stirring system.

Detailed Description

The present invention will be further described with reference to the following embodiments.

Example one

FIG. 1 shows an embodiment of the present invention, which comprises the following steps:

s10, the industrial wastewater enters a regulating tank 1 and is added with acid to regulate the pH value of the industrial wastewater to 1-3;

s20, adding hydrogen peroxide into the industrial wastewater, uniformly stirring, sequentially adding a remover and a magnetic catalyst, stirring for reaction, hydrolyzing the remover to obtain metal ions, wherein the metal ions comprise Fe²⁺、Cu²⁺The magnetic catalyst is hydrolyzed to obtain Fe²⁺、Fe³⁺；

The metal ions react with hydrogen peroxide under acidic conditions to form hydroxyl radicals which are oxidized with phosphorous to form Fe²⁺Promoting said oxidation reaction, Fe³⁺Co-precipitation with phosphorous;

s30, adding alkali into the industrial wastewater to adjust the pH value of the industrial wastewater back to 5-7, adding a flocculating agent, and stirring to form magnetic floccules in the industrial wastewater; the industrial wastewater containing the magnetic floccules flows into a sedimentation tank 2 for sedimentation, supernatant is obtained at the upper part of the sedimentation tank 2, and magnetic sludge is obtained at the bottom;

and S40, adjusting the PH value of the supernatant to be neutral and discharged after reaching the standard or entering a post-treatment process, and enabling the magnetic sludge to enter a magnetic catalyst recovery system 3 to recover the magnetic catalyst.

Specifically, in the present embodiment:

in step S10, the industrial wastewater is a mixed wastewater of an industrial park, the pH of the industrial wastewater is 1.2, and the total phosphorus of the industrial wastewater is 61.5 mg/L. In order to test the effectiveness of the method, 1L of wastewater is taken, and acid is added to adjust the pH of the industrial wastewater to 2.5, wherein the acid can be organic acid or inorganic acid.

In step S20, the remover comprises the following components by mass: 10 percent of aluminum sulfate; 5 percent of copper sulfate; 60% of anhydrous ferrous sulfate; 25 percent of magnesium sulfate.

In step S20, the magnetic catalyst is a mixture of ferroferric oxide and ferric oxide, and the mass ratio of the ferroferric oxide to the ferric oxide is 1: 1; the adding mass of hydrogen peroxide is 500mg, the adding mass of a remover is 500mg, and the adding mass of a magnetic catalyst is 300 mg; stirring and reacting for 20min after adding the medicament, adding 5% sodium hydroxide solution to adjust the PH to 5.0, adding 5ml of cationic PAM flocculating agent (the mass fraction is 0.1%), precipitating for 5min, and measuring that the total phosphorus in the supernatant is 0.47mg/L (meeting the requirement that the total phosphorus is less than 0.5 mg/L), and the sedimentation surface load of the sedimentation tank 2 is 22m³/(m²·h)。

Example two

This example is a second example of a sub-catalytic oxidation phosphorus removal process, and in this example:

in step S10, the industrial wastewater is a mixed wastewater of an industrial park, the pH of the industrial wastewater is 2.5, and the total phosphorus of the industrial wastewater is 6.3 mg/L. In order to test the effectiveness of the method, 1L of wastewater is taken, and acid is added to adjust the pH of the industrial wastewater to 2-3, wherein the acid can be organic acid or inorganic acid.

In step S20, the remover comprises the following components by mass: 20% of aluminum sulfate; 5 percent of copper sulfate; 50% of anhydrous ferrous sulfate; 25 percent of magnesium sulfate.

In step S20, the magnetic catalyst is a mixture of ferroferric oxide and ferric oxide, and the mass ratio of the ferroferric oxide to the ferric oxide is 3: 1; the adding mass of the hydrogen peroxide is 100mg, the adding mass of the remover is 90mg, and the adding mass of the magnetic catalyst is 100 mg; stirring and reacting for 20min after adding the medicament, adding 5% sodium hydroxide solution to adjust the PH to 6.0, adding 5ml of cationic PAM flocculating agent (the mass fraction is 0.1%), precipitating for 5min, and measuring that the total phosphorus in the supernatant is 0.2mg/L (meeting the requirement that the total phosphorus is less than 0.5 mg/L), and the sedimentation surface load of the sedimentation tank 2 is 25m³/(m²·h)。

EXAMPLE III

This example is a second example of a sub-catalytic oxidation phosphorus removal process, and in this example:

in step S10, the industrial wastewater is a mixed wastewater of an industrial park, the pH of the industrial wastewater is 1.5, and the total phosphorus of the industrial wastewater is 455 mg/L. To test the effectiveness of the above method, 1L of wastewater was taken and acid was added to adjust the pH of the industrial wastewater to 2.5.

In step S20, the remover comprises the following components by mass: 30% of aluminum sulfate; 2 percent of copper sulfate; 40% of anhydrous ferrous sulfate; 28 percent of magnesium sulfate.

In step S20, the magnetic catalyst is a mixture of ferroferric oxide and ferric oxide, and the mass ratio of the ferroferric oxide to the ferric oxide is 10: 1; the adding mass of hydrogen peroxide is 5000mg, the adding mass of a remover is 5000mg, and the adding mass of a magnetic catalyst is 1000 mg; stirring and reacting for 20min after adding the medicament, adding 5% sodium hydroxide solution to adjust the PH to 6.0, adding 5ml of cationic PAM flocculating agent (the mass fraction is 0.1%), precipitating for 5min, and measuring that the total phosphorus in the supernatant is 0.45mg/L (meeting the requirement that the total phosphorus is less than 0.5 mg/L), and the sedimentation surface load of the sedimentation tank 2 is 19m³/(m²·h)。

Example four

Fig. 2 shows an embodiment of the system for removing phosphorus by magnetic catalytic oxidation of the present invention, which comprises a regulating tank 1, a settling tank 2 and a magnetic catalyst recovery system 3: the adjusting tank 1 is communicated with the sedimentation tank 2, and the adjusting tank 1 is provided with a medicine for adding a medicamentThe bottom of the sedimentation tank 2 is communicated with a magnetic catalyst recovery system 3, and the magnetic catalyst recovery system 3 is communicated with the adjusting tank 1; the medicament comprises hydrogen peroxide, a remover, a magnetic catalyst and a flocculating agent, wherein the remover is hydrolyzed to obtain metal ions, and the metal ions comprise Fe²⁺、Cu²⁺The magnetic catalyst is hydrolyzed to obtain Fe²⁺、Fe³⁺The metal ions react with hydrogen peroxide under acidic conditions to form hydroxyl radicals which are oxidized with phosphorous to form Fe²⁺Promoting said oxidation reaction, Fe³⁺Co-precipitation with phosphorous; under the action of magnetic catalyst and flocculant, the suspended matter forms magnetic flocs.

The magnetic catalyst recovery system 3 comprises a sludge pump 31, a dispersion machine 32 and a magnetic circulation machine 33 which are sequentially arranged, the sludge pump 31 sends the magnetic sludge pump 31 at the bottom of the sedimentation tank 2 to the dispersion machine 32, the dispersion machine 32 separates the magnetic catalyst from the residual sludge, and the magnetic circulation machine 33 returns the magnetic catalyst to the adjusting tank 1.

In the practice of this example, the removal agent was hydrolyzed to yield Fe²⁺、Cu²⁺Reacting the metal ions with hydrogen peroxide to form hydroxyl radicals under an acidic condition, wherein the hydroxyl radicals efficiently oxidize the hypophosphorous acid; hydrolyzing the magnetic catalyst to obtain Fe²⁺、Fe³⁺，Fe²⁺Promoting said oxidation reaction, Fe³⁺Directly forming coprecipitation with hypophosphorous acid; and then, under the action of a magnetic catalyst and a flocculating agent, suspended matters in the industrial wastewater form magnetic floccules, the magnetic catalyst can be used as a magnetic core for solid-liquid separation and sedimentation, sedimentation is accelerated, the content of the suspended matters in the supernatant is reduced, the total phosphorus removal rate is improved, the pH of the supernatant is adjusted to be neutral and discharged after reaching the standard, the magnetic sludge enters a magnetic catalyst recovery system 3 to recover the magnetic catalyst, and the recovered magnetic catalyst can be recycled.

It should be understood that the above-described embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the embodiments of the present invention. Other variations and modifications will be apparent to persons skilled in the art in light of the above description. And are neither required nor exhaustive of all embodiments. Any modification, equivalent replacement, and improvement made within the spirit and principle of the present invention should be included in the protection scope of the claims of the present invention.